Apparatus for grinding or polishing precious stones.



H. DE VRIES & W. A. DUNALDSON. APPARATUS FOR samnma 0R POLISHINGPRECIOUS snmzs.

APPLICATION FILED APR- 25. 191

Patented Oct. 16, 1917.

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APPj/ICATIONFILED MI. 25. l8. 1,243,491. ,7

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H. DE VRIES & W. A. DQNALDSON. APPARATUS FOR GRINDING 0R POLISHINGPRECIOUS STONES.

APPLICATION F I LED APR. 25. um.

1,243,491. A 1 Patented 001,316,191?

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A TTORIIEYS Grinding or Polishing Precious Stones, of which thefollowing is afull, clear, and

UNITED STATES rignnr orFIon- HARRY bl FRIES, OI NEWARK, NEW JERSEY, ANDWILLIAM' A. DONALDSON, OF i BROOKLYN, NEW YORK.

APPARATUS IE'OB GBINDTNG OR POLISHING-PRECIOUS STONES.-

sex and State of- New Jersey, and (VILLIAM ARTHUR DoNALnsoN, a citizenof the United States, and a resident of the city of New York, borough ofBrooklyn, in the county of Kings and State of New York, have invented anew and Improved Apparatus for exact description.

The object of the invention lS tO provide a new and improved apparatusfor grinding or polishing diamonds and other precious stones, andarranged to enable the workman to correctly set the dop with a view togrind or olish the facets of the precious stone but as to number and thedesired angle.

In order to produce the desired result, use

is made of a dop-holding device, and means for adjusting saiddop-holding device in an arc with the center 'of the stone held by thedop-holding device located outside of the arc. Use is also made of aspindle, a sector held on the lower end of the spindle and hav ing itscenter in the axis of the spindle above the sector, a carrier adjustablyheld on' the said -sector and extending outward therefrom, a dop. holderrotatably mounted .on the said carrier and a dop held on the saidcarrier and adapted to carry the precious stone to be ground orpolished.

A practical embodiment of theinvention is represented in theaccompanying draw ings forming apart of this specification, in whichsimilar characters of reference indicate corresponding parts inall theviews.

Figure 1 is a side elevation of the apparatus for grinding or polishingpreciousstones, part of the table being shown broken out; i

Fig. 2 is an enlarged plan view of the frame carrying the dop-holdingdevice;

Fig. 3 is a sectional side elevation of the same with a portion of theframe shown in elevation; I i

Fig. 4 is an enlarged front elevation of the same; a Fig. 5 is aninverted plan view of the hearing for the sector spindle; I

Fig. 6 is a sectional side elevation of the carrier of the (lop-holdingdevice, the section being on the line 6-45 of Fig. 7;

Specification of Letters Patent.

ing forthe spindle.

Patented Oct. 16, 1917. Application filed-April 25, 1917. Serial No.164,394:

Fig. an inverted plan view of the same i Fig. 8 is a sectional plan viewof the car rier in position on the sector, thesectio being on the line88 of Fig. 3; i

Fig. 9 isa plan view of the dop holder;

Fig; 10 is a side elevation of .the dop holder and part of the carrier;

Fig.,11 is a sectional plan view of a portion of the carrier with thebracket for hold-, ing the stone support; and

Fig. 12 is a side elevation of the bush- The lap 10 is arranged a shortdistance above a table 11 and itsvertically disposed shaft 12 isconnected by a suitable couptling 1.3 with the head l i of a motor sizeof a motor 16 of any approved construction, 7 preferably, however, ofthe electric type,

so that the lap 10 isdirectly run from the motor whenever the latter isstarted. The

upperend of the lap shaft 12 is journaled depending posts 32 in each ofwhich screws a screw 33 provided at its lower end with in an arm 17mounted on a bracket 18 ata head 34 resting on the top of the table 11,=

it being understood that by adjusting the 9.0 ered to locate theprecious stoiie 31 in screws 33 the frame can be raised or lowproperrelation .to the lap 10, A look nut 35 screws on the screw 33 againstthe under side of the corresponding post 32 to securely lock the screw33 in place after the desired adjustment has bee'n made. The frame 20provided atits rear end with the 'usual orizontally disposed rod 36 heldagainst lateral displacement by abutting against a vertical pin 37rising from a plate 38 adjustably secured by a bolt or other fastening.means 39 to the top of the table 11.- v The forward end of the plate 38is provided with an upwardly extending pin 37 en gaging the frame 20 atthe side opposite the one at which the pin 37 engages the rod 36, thusholding, the frame against displacement in an opposite direction.

The frame 20 is provided with a detachable head 40 provided with avertically dis posed dovetail tongue 41 engaging a similarly constructeddovetail groove 42 formed in the forward end of the frame 20. A setscrew" 43'screws in the frame 20 against a liner 44 abutting against oneside of the tongue 41 to securely fasten the head 40 in positionon' theforward end of the frame 20. In the head 40 is mounted a bearing 45provided. at its lower end with an annular flange 46, the under side ofwhich is beveled and provided with a graduation (see Figs. '4 and 5)corresponding to the points of a compass. In the bearing 45 is arrangeda bushing engaged by a spindle 51 provided at its upper end with athreaded portion 52 on which screws a nut 53 resting on the top of thebushing 50, and the spindle 51 is provided at its lower end with a pin54 engaging a notch 55 formed in the bushing 50 so that the spindle andbushing turn to gether. The bushing 50 is provided with an annulargroove 56 into which projects the inner end of a screw- 57 screwing inthe a head 40 and the bearing 45, as plainly indicated in Fig. 3. Bythis arrangement the bushing 50 is held against upward or down wardmovement in the bearing 45. A set screw 58 screws in the head 40 and thehearing 45 against the bushing 50 to lock the latter in place after thedesired adjustment of the spindle 51 has been made. 7

On the lower ,end of the. spindle 51 is secured or formed the web 60 ofa sector 61, preferably in the form of a dovetail tongue, engaged by adovetail groove 62 formed on a carrier 63 forming part of thedop-holding device 30. One or two set screws 64 screw in the carrier 63against a liner. 65 abutting against one side of the sector 61 (see Fig.8) to securely hold the carrier 63 in the desired adjusted position onthe sector 61. The sector 60 is provided on its peripheral face with asegmental gear wheel 66 in mesh with a pinion 67 secured on a shaft 68extending transversely and journaledin the carrier 63. The front end ofthe shaft 68 is provided with a head 69 adapted to be taken hold of bythe operator for turning the pinion 67 to slide the carrier 63 around onthe sector 61 according to the direction in.which the shaft 68 is turnedat the time, it being, however, understood thatduring this ad ustingmovement ofthe carrier 63 on the sector 61 the said screws 64 areloosened. On the under side of the carrier 63 is arranged a recess 70into which fits a pivot 71 in the form of an inverted cup projectingcentrally from a dop holder 72 carrying the dop 73 in which the preciousstoneZBl is mounted in the usual manner.

.The' dop 73 is of conical shape and the pre-' cious stone 31 is'mounted in the apex of under side of the dop holder 72 and securedindicated in Fig. 3.

thereto by a coupling nut 75 engaging the flange 74 and screwing on thedop holder 72. The base of the dop 73 is providedwith a reduced portion76 abutting against a flange 77 formed on the under side or open'end ofthe cup-shaped pivot 71 to hold the said pivot securely in position inthe dop holder 72. j

In order to hold the dop holderTQ yieldingly in position on the carrier63 use is made of a screw 80 extending in the pivot 71 and passingthrough the closed end thereof toscrew in the carrier 63, as plainly Thespring 81 is arranged Within the pivot 71 and is coiled around'theportion of the screw 80 extending within the said pivot 71. The lowerend of the spring 81 rests on a washer 82 held on the head 83 of thescrew 80, and the upper end of the said spring 81 abuts against theunder side of the. closed end of the pivot 71. The opposed faces of thecarrier 63 and the dop holder 72 are provided with teeth 85 and 86,respectively, of which the teeth 85 are preferably thirty-two in numberwhile the teeth 86 in mesh with the teeth 85 are preferably four innumber (see Fig. 9) and are disposed equal distances apart. Theperipheral face of the dop holder 72 is provided with an annulargraduation 87 having thirty-two marks spaced equal distances apart andnumbered consecutively beginning at one of the teeth 86, as plainlyshown in Fig. 10. It is understood that this graduation 87 serves to aidthe operator to adjust the dop holder 7 2, the dop 73 and the preciousstones 31 to set the stone in proper relation to the lap and to thenumber of facets. It is understood that the dop holder 72 can be readilyturned on the carrier 63 owing to the yielding connection by the use ofthe spring 81 and the pivot 71, and at the same time the dop holder 72is securely locked in the adjusted position by its teeth .86 engagingthe corresponding teeth 85 on the carrier 63. It is further understoodthat v the spring 81 readily yields on turning the dop holder 72 toallow the teeth 86 to glide is reached.

In order to properly support the stone 31 in the dop holder 73, use ismade of the usual rod 90 provided with a claw 91 engaging the projectingend of the precious stone 31 held in the dop 73, as plainly indicated inFigs. 3 and 4. The rod 90 is held adjustably in an up and down directionin a bracket 92 attached to the carrier 63, and the rod is fastened inthe adjusted position by a set screw 93 screwing in the bracket 92 andagainst thefrod 90, as plainly shown in Fig. 3.

In order to indicate the exact angular positionof the facets of thestone 31 relative to' the face of the lap 10, use is made of a i'i'sdegree scale .100 marked on the web 60 of the sector (31, and a pointingmark 101 is marked on the face of the carrier (see Fig. l) to registerwith any one of the degree marks on imparting a sliding movement to thecarrier 03 on the sector 61., as above mentioned. \Vhen the severalparts are in the position shown in Figs. 1 and 3 then the mark- 101 isopposite Zero of the graduation-100 and the .axis of the dop 73 isvertical and parallel with the axis of the spindle 51 and in whichspindle axis the center of the sector 61 is located. On sliding thecarrier 63 downward and forward on the sector 01 the position of thestone relative to the lap -10 is correspondingly changed thecorresponding degree indicating the angle of a facet relative to theface of the lap. Thus by the arrangement described llle Operator canquickly and accurately set the dop with a view to correctly hold thestone 31 in position relative to the lap 10.

It will be noticed that by making the head 40 detachable onthe frame 20,the dop holding device can be readily detached from the frame wheneverit is desired to do so.

.It will also be noticed that by making the spindle 51 carrying thesector 61 and the dop-holding device 72 turnaole in the head 40, it isevident that the stone 3]. can be moved in contact with differentportions of the face of the lap 10 to allow of utilizing the entire faceof the lap for grinding purposes.

Having thus described our invention, we claim as new and desire tosecureby Letters Patent 1. In an apparatus for grinding or polishingprecious stones, a frame, a vertically disposed spindle held on the saidframe and provided at its lower end with a sector, the

- center of which is located in the axis of the spindle above thesector, a carrier slidably mounted on the peripheral face of the saidsector, a rotatably and yieldingly mounted dop holder on the saidcarrier, and a dop removably held in the saiddop holder.

2. In an apparatus for grinding and polishing precious stones, avertical spindle having a sector at its lower end, a. carrier adjustablymounted on the sector, a rotatably and yieldingly mounted dop holder onthe carrier, and means for locking the dop holder in position.

:3. In an apparatus for grinding and polishing precious stones, avertical spindle having a sector on its lower e d, a carrier adj ustablymounted on the sector, and a rotataloly and yieldingly mounttfil ,dop.holder on the carrier, the faces of the carrier and dop holder havinginterengagi'ng teeth.

4. In an ap iaratns for grindln or polishing precious stones, a dopprovided with a base flange, :1 dop holder provided with a clamping notengaging the said flange to fasten the dop in place on the holder, thetop of the holder being provided with teeth, a carrier provided at theunder side with teeth adapted to be engaged by the teeth of the said dopholder, an inverted cup held centrally on the said dop holder andmounted to turn in said carrier, a pivot held on the said carrier andextending into the said cup,

and a spring held on the said fpivot and.

bearing against the said cup.

5. In an apparatus for grinding and polishing precious stones, a'carrierhaving a recess, an inverted cup carried by the holder and extendinginto the recess of the car? rier, a pivot extending through the cup intothe carrier and a sprlng on the pivot and bearing against the cup, andmeans for preventing the dop holder from turning.

6. In an apparatus for grinding and polishing precious stones, a carrierhaving teeth on its lower face and provided with a recess in said face,a dop holder having teeth on its upper face engaging the teeth of thecarrier, an inverted cup carried by the holder and extending into therecess of the carrier, a pivot extending through the cup into thecarrier, and a spring on the pivot and bearing on the en p HARRY onVRIES. WILLIAM A. DONALDSON.

